In the pharmaceutical sector, liquid substances are often stored in glass ampoules. Such liquid substances, for instance in particular the liquid component of a bone cement, might be volatile, chemically aggressive, or toxic.
Therefore, glass ampoules are particularly suitable for such liquids, since they are chemically stable and at the same time impermeable to gases and liquids, so that only very small amounts, if any, of components of the liquid stored in the ampoule will exit from the package, or only very small amounts, if any, of gases such as oxygen will enter into or exit from the package that is formed when the latter consists of a glass body sealed by flame-melting, such as an ampoule, for example.
Such an ampoule can for instance be used to store the monomer component of a bone cement, such as methyl methacrylate, for several years without loss. This is achieved in glass ampoules that have a neck which must be broken before extraction.
However, such break-open ampoules are not optimal in handling. For example, slivers might be produced implying a risk of injuries for the user or contamination of the liquid. Furthermore, the extraction of the liquid for example by means of a syringe is complicated and entails an elevated risk for the ampoule to be held inclined to such an extent that liquid drips down or that the quantity of the extracted liquid is inaccurate or injuries may be caused.
Furthermore, packages are known which are sealed with a septum. Such a septum usually consists of an elastomeric layer, which is crimped onto the collar of a vial with an aluminum crimping cap.
Such packages have the advantage that they can be perforated, for example using a hollow needle, in order to extract the liquid. Once the hollow needle has been retracted, the septum closes so that there is at most a slight risk for further liquid to inadvertently escape from the package or for contaminants to enter the package.
However, it has been found that such closures are not sufficiently impermeable for many applications, even if high-quality multi-layer seals are used. Over the storage period, evaporation of the liquid contents occurs.
For example the monomer component of a bone cement, such as methyl methacrylate for example, will outgas which implies a loss of liquid. Besides inaccurate dosing, this may also cause an unintentional partial reaction of the powder component if the liquid component and the solid component are stored side by side in a packaging.
Another problem is insufficient impermeability to gases that might enter the vial and react with the contents. This may also pose a problem when the package is sterilized exteriorly using a gas. In particular highly toxic ethylene oxide is used for sterilization of the package, which must not get into the package, under no circumstances, even not in small quantities.